Re: Rationale for RLIMIT_MEMLOCK?

[Matthias Andree <matthias.andree@gmx.de>]

Joerg Schilling wrote:

> RLIMIT_MEMLOCK did first apear in BSD-4.4 around 1994.
> The iplementation is incomplete since then and partially disabled (size check 
> for mmap() in the kernel) on FreeBSD as it has been 1994 on BSD-4.4
> 
> FreeBSD currently uses a default value of RLIMIT_INFINITY for users.

And while it does that (or in fact, rather not distinguish between root and
unprivileged users), mlock() and mlockall() are privileged operations on
FreeBSD.

> I could add this piece of code to the euid == 0 part of cdrecord:
> 
> LOCAL void 
> raise_memlock() 
> { 
> #ifdef  RLIMIT_MEMLOCK 
>         struct rlimit rlim; 
>  
>         rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY; 
>  
>         if (setrlimit(RLIMIT_MEMLOCK, &rlim) < 0) 
>                 errmsg("Warning: Cannot raise RLIMIT_MEMLOCK limits."); 
> #endif  /* RLIMIT_NOFILE */ 
> } 

Except that your new #endif comment is wrong, that is exactly what I
suggested and what I've tried and found working.
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